1. Field of the Invention
The invention relates to therapeutic agents which are novel derivatives of 4-amino-2-(piperazin-1-yl) or homopiperazin-1-yl)quinazoline. Such compounds are useful as regulators of the cardiovascular system, and in particular, in the treatment of hypertension.
2. Description of the Prior Art
The therapeutic properties of a variety of quinazolines, including 4-amino-2-[(4-substituted)piperazin-1-yl]quinazolines are well known. U.S. Pat. No. 3,511,836 describes 4-amino-6,7-dialkoxy-2-[(4-substituted)-piperazin-1-yl]quinazolines wherein the 4-substituent is benzoyl, thenoyl or furoyl. The products are valuable hypotensive agents. Analogous 6,7,8-trialkoxy compounds, also useful as hypotensive agents, are described in U.S. Pat. No. 3,669,968.
Related antihypertensive compounds wherein the 4-substituent on the piperazinyl group is oxazolyl, thiazolyl, isoxazolyl or isothiazolyl are disclosed in U.S. Pat. No. 4,001,237.
German Specification No. 2,646,186 describes, as hypotensive agents, a series of 4-amino-6,7-dimethoxy-[2-(4-substituted)piperazin-1-yl]quinazolines wherein the 4-substituent is tetrahydro-2-furoyl or tetrahydropyran-2-carbonyl.